"A little rust", yeah, right.
You do know that they've got a steel frame that's cladded with aluminum panels, right? And the rustproofing wasn't that great from the factory.
Check very carefully for holes in the steel structure, missing trunk floors and other small details. Also check the two-part hatch, chances are that it's somewhere between bubbly and holey.
The Rover V8 is notorious for eating cams if the oil isn't changed very regularly and the transfer box likes to get stuck in one position - usually High, but check that you can get it out of High and back in. They're also not very powerful but make up for it in fuel consumption. The one I had in the UK for a short time, I ran on CNG (it had already been converted) as that lowered the running costs from "atrocious" to "stupidly expensive", being approx 1/2 price of petrol over there.
The front main swivel joints (can't recall what they're called, but they're obvious - it's the part that rotates and carries wheel spindle when you turn the steering wheel) on the axle need new seals regularly, otherwise the oil/grease in in the joint will leak out, with expensive consequences. Basically if the joint looks dry, chances are you'll have to look at it.
Edit: In the UK, the "thing" is called a swivel ball assembly.
Also, if it doesn't mark its territory, chances are other fluids need topping off.
Electrics - well, make sure the stuff you'll need is working as it's unlikely to have all electrics working.
Also, I wouldn't touch one with air suspension - they always leak and if it goes wrong, you'll more or less have to converted to coil suspension as fixing the air suspension is painfully expensive.
Sanity is vastly overrated.
. Bright yellow, just ridiculous 
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